MAF: Which to use for what application

[heptone182]

Not sure if I can remember this question being asked but, I'm wondering which MAF off which vehicle or aftermarket are people running on their cars and for what application? The reason I'm asking is, personally, I'm about to run an arc-2 setup with 750cc injectors and I want to swap the stock MAF to something that would pair nicely with those mods. Matt recommended a 2000 or newer SVT Lightning OEM MAF. Obviously I trust his judgement, I'm just wondering what you all have setup and your thoughts on what you based your decision off of.

[TurboSinceBirth]

Not sure if I can remember this question being asked but, I'm wondering which MAF off which vehicle or aftermarket are people running on their cars and for what application? The reason I'm asking is, personally, I'm about to run an arc-2 setup with 750cc injectors and I want to swap the stock MAF to something that would pair nicely with those mods. Matt recommended a 2000 or newer SVT Lightning OEM MAF. Obviously I trust his judgement, I'm just wondering what you all have setup and your thoughts on what you based your decision off of.

The MAF he is talking about is a 92mm plastic Ford MAF on the Lightnings and Cobras. I currently have one with the ARC-2. I will either be keeping it with the ARC-2 zero'd out as a MAF upgrade when I install the flashed ECU or I will be using an EVO 8/9 MAF instead. It all depends on what engine management setup you want to use as to which MAF you end up with.

ARC-2: Ford MAF sensors and housings. There's quite a few but the ones sold with the kits are 87 and 92mm currently. 83mm used to come with it a long time ago.
MAFT: GM MAF 3" or 3.5"
Flashed ECU: EVO 8/9 MAF with a pigtail harness and two value changes in the ECU makes it drop in. You can use any other piggyback with it such as ARC-2 or GM MAF & MAFT for the MAF upgrade but that adds more expense than the EVO MAF itself.
The other piggybacks use speed density.

What are you mods and desired power output? That would help us with choosing the right MAF for you.

[heptone182]

Well currently I'm running DR-16T's, FMIC, Walbro fuel pump, straight through borla exhaust with a stillen DP and gonna be swapping in those 750cc injectors. I do have a 87mm Granatelli MAF sitting in a box for a 96-98 Mustang GT, but not sure of my limitations with it. Plus since its calibrated for the GT at for 19lbs/hr injectors, not sure if it's a good idea since the SVT MAF's are set at 24lbs. That's another thing... what is the conversion from cc/min to lbs/hr? Not sure I understand that too much. Shooting for 500whp

Update: found the conversion on cc/min to lbs/hr plus the explanation on Jeff L's site here
http://www.stealth316.com/2-injectortypes.htm

[TurboSinceBirth]

Well currently I'm running DR-16T's, FMIC, Walbro fuel pump, straight through borla exhaust with a stillen DP and gonna be swapping in those 750cc injectors. I do have a 87mm Granatelli MAF sitting in a box for a 96-98 Mustang GT, but not sure of my limitations with it. Plus since its calibrated for the GT at for 19lbs/hr injectors, not sure if it's a good idea since the SVT MAF's are set at 24lbs. That's another thing... what is the conversion from cc/min to lbs/hr? Not sure I understand that too much. Shooting for 500whp

If it came with your ARC-2 it should work fine. Even if I didn't I don't see any problems. I don't think it matters as much what injectors the MAF are calibrated for because the ARC-2 itself adjusts the fuel curve for different injector sizes. I'm surprised you didn't go with 550cc injectors since 750s are a little big for DR-16Ts. I pulled my ARC-2 off a DR-16T 550cc setup that made great pump gas numbers. Running a larger injector than you need with a piggyback will advance the timing which is going to bring on knock sooner resulting in running less boost on pump. If you're on race gas or ethanol it won't really matter.

As far as the limitation of the 87mm MAF I wouldn't worry about it. It's probably good for 7-800hp. I know Matt has said before when he switched to the 92mm MAF but he was pushing quite a bit of power. The difference in hp gain between the two is going to be very small until you upgrade to some bigger TD05 or T3 turbos running all out. You won't be able to max out the 16T turbos on that MAF.

[Greg E]

Well currently I'm running DR-16T's, FMIC, Walbro fuel pump, straight through borla exhaust with a stillen DP and gonna be swapping in those 750cc injectors. I do have a 87mm Granatelli MAF sitting in a box for a 96-98 Mustang GT, but not sure of my limitations with it. Plus since its calibrated for the GT at for 19lbs/hr injectors, not sure if it's a good idea since the SVT MAF's are set at 24lbs. That's another thing... what is the conversion from cc/min to lbs/hr? Not sure I understand that too much. Shooting for 500whp

Update: found the conversion on cc/min to lbs/hr plus the explanation on Jeff L's site here
Stealth 316 - Fuel Injectors

I like how you're cautiously approaching modifying your car and trying to understand how and why things work the way they do.

The ratings for the MAFs shouldn't be an issue because you're not sending accurate airflow information to the ECU anyway. The difference between a 19 and a 24lb MAF is the difference between an extra click or two to the base knob on the ARC2.

[heptone182]

I like how you're cautiously approaching modifying your car and trying to understand how and why things work the way they do.

The ratings for the MAFs shouldn't be an issue because you're not sending accurate airflow information to the ECU anyway. The difference between a 19 and a 24lb MAF is the difference between an extra click or two to the base knob on the ARC2.

Thanks! Yeah I am be VERY cautious for that reason exactly. Sure there's a bit of experimentation, but nothing too outrageous without knowing how things work first. I went ahead and put in the 90mm svt MAF and am going to leave the granatelli one out just because I notice the screws holding the sensor seem to get loose. Maybe it's just mine but I feel safer knowing the turbos aren't going to eat my sensor for lunch! I'm sure lock tight could work but I'm just gonna stick with the 90mm. Oh and if you cancontribute to this thread, please do!!!>>>> http://www.3sgto.org/f104/official-a...ead-10114.html

[TurboSinceBirth]

Few points:

*You can NOT leave the ARC2 unit zeroed out with the flash ECU. It's not like the MAFT which sends a calculated modulation based off the sensor voltage. You need to tune the frequency. Not sure why they set it up that way.

*You can tune the timing, injector scaling/latency tables and just use the ARC controller for real time tuning. You may not even want to touch the fuel map. In fact, I see most people going this route with the flash ECU because you can't tune the flash ECU live. This is how I tune all ARC2 and MAFT cars with the flash ECU. Works great. Check out Toni's dyno thread.

*Both the ARC and the MAFT give you consistent results with the simplicity of tuning with the 4 basic knobs. Set the mid to -7 and tune the others like you would with any other setup. With the MAFT, tune the base knob and leave the rest alone.

The trade off is the ECU won't know the exact airflow so this may cause headaches for ECU controlled boost/ fuel cut at first, but you can still tune it. It's all a matter of taking logs and adjusting the tables based on the airflow the ECU is seeing.

*If you tune the motor so that it all falls within the compensation range of closed loop, there should be absolutely no reason why your tune will drift. These Hotwire ford and GM MAFs are all relative sensors. NOT absolute like our Karmen Vortex meters. You really don't need air temp/ baro compensation because your base signal coming from those MAFs are already compensated.

IN FACT you don't even need to hook up the temp and baro signal wires from the MAFT or the ARC with the flash ECU. Just disable the CELs and the ECU won't adjust the load calculation for those factors. Two less wires under the dash you need to worry about!

So if you want to run the ARC-2/flashed ECU combo would I set the mid to -7 and the rest to zero? I was going to have the flashed ECU do all of the injector scaling/latency values, timing, and fine tuning on the fuel map. The ARC-2 would be there to use the Ford MAF sensor. I could use the ARC-2 for real time tuning but I'm not sure if I would necessarily be using it for that except for maybe small changes in ethanol content say if I got E85 but it varied from 70-85% content. Otherwise, I would just use a 91 map and E85 map. I don't switch fuel often enough where it's a pain to carry around my laptop so that's no problem. I guess I'm trying to fully understand how they work together without actually trying it physically yet. I'm sure it will make more sense once I get to play around with it.

This is why I gave up on it. There's literally nothing holding those delicate screens in place. It's very easy to pop them out. The metal is like tin foil.

I figured as much. It's sitting in my closet and I may just get rid of it. If my power level wasn't as high I'd run it for sure but now it doesn't sound like it's worth my time chasing. I like the fact that you change two values and you're done with it. We'll see what happens in the future with the flashed ECU development. I sincerely appreciate everyone's efforts on it for the past few years. This is a huge development for our platform.

[Greg E]

So if you want to run the ARC-2/flashed ECU combo would I set the mid to -7 and the rest to zero? I was going to have the flashed ECU do all of the injector scaling/latency values, timing, and fine tuning on the fuel map.

No I'm sorry. I didn't say that correctly. You still need to tune the other 3 dials but you'd start off with the settings as if you still had stock fuel injectors. Since your injectors will be scaled properly, the base knob can stay closer to zero.

[Greg E]

BTW, switchable maps are in the near future.

[heptone182]

I'm probably gonna do the E85 conversion here soon as well, so I'm probably gonna be sticking with those 750cc's for future upgrades as well. That'll probably be when I switch to the 92mm MAF then. Thanks Michael